Forming means for profile grinding wheels



May 16, 1961 H. s. HALLEWELL FORMING MEANS FOR PROFILE GRINDING WHEELS 5 Sheets-Sheet 1 Filed May 15, 1959 TTOEWE) May 16, 1961 H. s. HALLEWELL FORMING MEANS FOR PROFILE GRINDING WHEELS 3 Sheets-Sheet 2 Filed May 15, 1959 4 ill [\il 11:

m/vavroe H-S HAl-LEWELL 770R EV May 16, 1961 v H. s. HALLEWELL 2,984,234

' FORMING MEANS FOR PROFILE GRINDING WHEELS Filed May 15, 1959 s Sheets-Sheet s /Nl NTO2 f/ S HALLEWE 1 A ORA/E) United States Patent FORMING MEANS FOR PROFILE GRINDING WHEELS Harold S. Hallewell, Connaught Works, Uxbridge Road, Hillingdon Heath, England Filed May 13, 1959, Ser. No. 812,898

3 Claims. (Cl. 125-11) The present invention relates to forming means for profile grinding wheels, and provides an apparatus for the formation on a grinding wheel of a profile which is the complement of a profile required to be ground thereby on a tool, die, gauge or other workpiece. The profile is formed by means of a truing tool point which is arranged for movement with a follower member adapted to follow a template, so that the profile of the template is reproduced on the circumference of the grinding wheel.

The invention has for its object to provide a simple apparatus of this character with convenient hand-operated means for maintaining the template follower in contact with the template, for rocking the tool spindle to maintain the tool normal to the profiled surface of the grinding wheel, and for simultaneously controlling the direction and speed of traverse of the tool across the grinding wheel periphery.

' With this object in view the forming means according to the present invention comprises a slide movable to and fro by power-operated driving means, a lever pivoted between its two ends on the slide for rocking movement about an axis normal to the directions of movement of the slide, a tool spindle mounted on one end of the lever for rocking movement with respect to the lever about an axis parallel to the rocking axis of the lever, a control unit mounted on the other end of the lever for rocking movement about an axis parallel to the axis of the tool spindle and embodying means for controlling the power-operated driving means to vary the speed and direction of movement of the slide, means interconnecting the control unit and tool spindle so that rocking movements of the former are transmitted to the latter, and a handle whereby the rocking movements are imparted to the control unit, the said handle being in addition rotatable and movable to and fro in directions aligned with or parallel to its axis of rotation with respect to the control unit, to operate the speed and direc-' tion controlling means of the control unit.

A preferred embodiment of this invention will now be described by way of example, with reference to the accompanying drawings in which Fig. 1 is a vertical section of a grinding wheel forming apparatus,

Fig. 2 is a longitudinal section of this apparatus,

Fig. 3 is a partly sectioned plan view of one end of a lever forming part of this apparatus, and

Fig. 4 is a plan view partly cut-away and sectioned of the other end of the same lever.

Referring to the drawings, a slide block 11 is mounted on two cylindrical guide bars 12 for sliding movement in two opposite directions indicated by arrows A and B (Fig. 2). The guide bars 12 are arranged parallel to the axis of the grinding wheel 13 on which the desired profile is to be formed and are supported at their ends in an elongated base constituted by casting 14. They are located side-by-side below and laterally displaced from the lowermost point on the circumference of the grinding wheel 13, as shown in Fig. 1. Depending forked lugs 16 on the underneath of the slide block 11 are adapted to be connected to the piston rod (not shown) of a hydraulic motor by which the slide block 11 is reciprocated along the guide bars 12 under the control of a valve which will be described later.

Formed integrally on top of the slide block 11 are brackets 17 as shown in Figure 2 carrying coaxial bearings 18 for pivot pins 19 as shown in Figure 3 on a lever arm 21. The axis of the bearings 18 and pivot pins 19 is normal to the vertical plane containing the axis 15 of the grinding wheel. A rocking tool spindle 22, mounted in ball bearings 23 in one end of the lever arm 21 for rocking movement about an axis parallel to the axis of the bearings 18 and pivot pins 19, has fixed to one of its ends an arm 24 carrying a forming tool 25 and to its other end a template follower 26. The template follower 26 is provided in known manner with guide wings 27. The forming tool 25 is so shaped and dimensioned that, when it engages the circumference of the grinding wheel 13, the axis of the rocking tool spindle will be tangential to the circumference of the grinding wheel at the point of engagement of the forming tool with the wheel. Pivotally mounted in the other end of the lever arm 21 for rocking movement about an axis 30 parallel to the axis of the bearings 18 and pivots 19 is the casing 28 of a hydraulic control valve which constitutes a control unit for the forming means. To the casing 28 is fixed a depending lug 29 (Fig. 2). The lower end of the lug 29 is connected by a link 31 to a depending arm 32 as shown in Figure 1 on the rocking tool spindle 22.

A valve piston 33 (Fig. 4) arranged for rotation and axial sliding movement in the valve casing 28, has fixed to its outer end a handle 34. A collar 50 on the valve piston 33 close to its inner end serves as an abutment for one end of each of two helical compression springs 35, 36 which oppose respectively inward movement of the valve 33 and handle 34 in the direction of the arrow C and outward movement thereof in the direction of the arrow D.

The valve casing 28 is formed with an inlet port 37 and two outlet ports 38, 39 as well as with two further ports 41, 42 which are connected respectively with opposite sides of the piston (not shown) of the hydraulic motor by which the slide block 11 is moved to and fro. Two ports 43, 44 extend through the valve piston 33, the arrangement being such that, when the valve piston 33 is pushed inward by the handle 34 in the direction of the arrow C, the port 44 interconnects the inlet port 37 with the port 42, and the port 43 interconnects the outlet port '38 with the port 41, and that, when the valve piston is pulled outward by the handle 34 in the direction of the arrow D, the port '43 interconnects the inlet port 37 with the port 41 and the port 44 interconnects the outlet port 39 with the port 42. A supply of oil under pressure from a source (not shown) is connected to the inlet port 37 and return pipes (not shown) are connected to the outlet ports 38, 39. Consequently, when the handle 34 is pushed in, the slide block 11 will be moved in the direction of the arrow A in Fig. 2 and, when it is pulled out, the slide block 11 will be moved in the direction of the arrow B.

The ports are also arranged in known manner so that, when the handle is either pushed in or pulled out, the flow of oil under pressure to the hydraulic motor can be increased by turning the handle 34 and valve piston 33 clockwise (Fig. 4) and reduced by turning them counterclockwise.

A template 45 is attached in known manner to a support 46 carried by brackets 47 fixed to the side of the casting 14 remote from the grinding wheel 13, the temv p 1 2,984,234 r plate being positioned with its main surface areas in planes normal to the axis of the tool spindle 22. The template follower 26 is arranged to move along the profiled lower edge of the template 45.

By means of the handle 34, the casing 28 of the hydraulic control valve can be rocked about its axis, and its rocking movement will be transmitted by the link 31 to the tool spindle carrying the template follower 26. The template follower can thus be maintained normal to the surface of the template at its point of contact thereby ensuring that the forming tool 25 is likewise maintained normal to the surface of the grinding wheel 13 at its point of contact therewith.

I claim:

1. A forming means for profile grinding wheels comprising an elongated base, a slide block slidably mounted on the base for sliding to-and-fro movement relatively thereto, means adapted for moving said slide block toand-fro, a lever arm pivotally mounted between its two end regions on said slide block for rocking movement about an axis normal to the directions of to-and-fro movement of the slide block, a tool spindle pivotally mounted on said lever arm near one end of said lever arm for rocking movement relative thereto about an axis parallel to the rocking axis of said lever arm, a template follower carried on one end of said tool spindle axially aligned therewith, an arm secured to the other end of said tool spindle and extending in a generally axial direction from said tool spindle, a forming tool carried on said arm and having its cutting edge aligned with the axis of said tool spindle, said forming tool being directed generally radially outward of the axis of said tool spindle, a control unit pivotally mounted on said lever arm near the other end of said lever arm for rocking movement about an axis parallel to the rocking axis of said lever arm, means embodied in said control unit for controlling the driving means to vary the speed and direction of movement of said slide block, means interconnecting the control unit and the tool spindle so that rocking movements of the former are transmitted to the latter, and a handle whereby rocking movements may be imparted to the control unit, said handle being in addition rotatable with respect to the control unit and mova ble to-and-fro in directions aligned with or parallel to its axis of rotation, with respect to the control unit, to operate the speed and direction controlling means embodied in the control unit.

2. A forming means for profile grinding wheels according to claim 1, wherein said means interconnecting said control unit and said tool spindle are constituted by a link pivotally connected at one of its ends to a lug depending from said control unit and pivotally connected at its other end to an arm depending from said tool spindle.

3. A forming means for profile grinding wheels according to claim 1, wherein said means for moving said slide to-and-fro is constituted by a hydraulic motor and said control unit is constituted by a hydraulic control valve including a cylinder, a piston arranged in said cylinder for rotation about and for limited sliding movement along the axis of said cylinder, the piston and cylinder being provided with ports for the flow of hydraulic fluid and the ports being arranged so that the direction of flow of the hydraulic fluid through the motor is dependent upon the axial position of the piston and the rate of flow of the hydraulic fluid is dependent upon the rotary setting of the piston.

References Cited in the file of this patent UNITED STATES PATENTS 2,008,128 Condon et al. July 16, 1935 2,170,304 Herfurth Aug. 22, 1939 2,294,493 Wilson Sept. 1, 1942 2,503,646 Wilson Apr. 11, 1950 2,602,437 Tancred July 8, 1952 

